Transmission tower arms



Jan. 31, 1933. c. M. GOODRICH TRANSMISSION TOWER ARMS Filed March 16,1929 ,2 Sheets-Sheet 2 ImQenaT: (Ham/c5? whee/1 Ciaoaemw T 1 War/my?Patented Jan. 31 1933 CHAUNCEY men eoonqarorr, or wrmsoa; NTAB ,.GAfi-DATRANSMISSION TOWER AIR/MS Application filed March 16, 1929. Serial No.347,576

This invention relates to transmission towers and more particularly tothe arm construction and mounting for such towers, and has for one ofits objects the provision of a hinged arm construction adapted to bemovable in the direction of the line.

Another object is to provide a hinged arm construction which will beyieldably held in position at right angles to the line.

In the drawings 2- i 1 Figure 1 is anelevation of a tower constructed inaccordance with this invention.

Figure 2 is a sectional view taken through the tower arm on the line11-11 of Figure 1.

Figure 3 is a sectional plantaken on the line III-III of Figure 1.

Figure 4 is an enlarged plan of the tower.

Figure 5 is an enlarged fragmentary detail showing the hinge mountingfor the arm beams.

Figure 6 is a sectional view taken on the line VI-VI' of Figure 5. I v

Referring more particularly to the drawings the numeral 2 designates thelegs of the tower which are connected in the usual manner by horizontaland diagonal bracingmembers 3.

A triangular truss member 4.- is formed above the main body of the towerby angle members 5 which are extended upwardly from the upper ends ofthe tower legs 2 and are connected at their upper ends by anangle bar 5.

The upper ends of the legs 2 of the tower are connected by horizontalangle members 6 and 7 forming a rim. The side members 6, which extendparallel to the line, serve as sup ports for the arm beams to bedescribed and are connected to each other at a point interto the members6 and to the line are also connected by bars 9 which serve to furtherstiffen the upper end of the tower. A pair of horizontal plates 10 aresecured to each of the angle members 6 and are spaced apart by a spacingblock 12. Arm beams 13, preferably, although not necessarily, composedof wood, are hingedly supported by the plates 10 by being provided withtongue mediate their ends by a stiflening angle 8;

plates 14 which. are mountedibetwecn the plates 10 andheld in place bypivot pins or bolts 15.

Suitable-attachment plates 16 are secured V to the upperend of the trussmember sand extend in a direction transverseof. the line. Flexibletrussbars are connected-to each end of the plates 16 and extendoutwardly and downwardly to a point intermediate the ends g g of therespective arm beams 13 and have their.

outer .ends connected to attachment plates 18 secured'to the beams 13.'z r A plurality of insulator-hangers 19 are mounted on the arm beams13and the trans mission line cables are secured thereto.

load about their pivotalconnection 15 and the truss bars 17 will flex topermit? such swing. arm nearest the pull will flex and buckle while theother bar 17 will be in tension and remain as a support for the beam13.- The arched bar 17 will have a component in the direction of theapplied pull and will, theretore, have a tendency to return to normalpo-- 9 sition so as to assist in returning the beam 13 to normalposition.

- It will be understood that when one of the transmission line cablesbreaks the arm 5 beams 13 willswing only. a short distance, due to thefact that the unbroken cables and the resistance of the truss bars 17serve to counteract the pull of the broken cable.

While I have shown and described only 7 one specific embodiment of myinvention it will be understood that I do not fwish to be limitedthereto,since various modifications may be made without departingfrom'the scope thereof, as defined in the appended claims. i

I claim: Y

1. In a transmission tower, a transmission line supporting arm structurecomprising a pair of horizontally disposed vertically 1190 a i. Inoperatiomthe arm beams 13:are,nor.-.

The truss bar 17 0n the side of the spaced bracket plates secured tosaid tower at a point appreciablybelow the'upper end thereof, a beam, atonguerigidly secured to one end of said beam and projecting into the 5space between said bracket plates, a, vertically disposed pivot pinpassing through said plates and said tongue to form :a pivotalmounting-for said beam to permit horizontal swinging movement thereof,apair of truss 0 bars rigidly connected at transversely spaced o 7points to'the' upper end of said tower and to the opposite sides of saidbeam, said truss bars being adapted 'tonormall'y hold said beam againsthorizontal swinging movement 15 aboutsaidpivot'pin under normal loads,and

" beingwyi'eldabile to permit swinging of said" beam about said pivotpin underlabnormal loads. I V w 1 -24 In a transmission tower,transmission 2 line supportingarms extending outwardlyfrom oppositesides thereof in a direction 'transverse'to the line,-'e'ach' of saidarms com prisingY'a pairof horizontally disposed vertically spacedbracket 'platesfsecured to said I tower at a point appreciably belowtheupper 7 end of said-tower, a beam, a tongue rigidly secured to oneend of saidbeam and projecting into. thev space between said bracket,

plates, avertically disposed pivot pin pass ing. through said'plates andsaid tongue forming; a pivotal mounting for" said beam to permithorizontal swinging movement thereof, a pair ofitruss bars rigidlyconnected at: transversely spaced pointsto said: tower .35 at points.appreciably above saidv bracket plates and to the opposite'sides of saidbeam, v r

said-.'truss bars being adapted to r normally hold said beam againsthorizontal swinging" movement. about said pivot pin under normal l 0loads, and, being yieldable to permit swing r I V V 1 ing of said beamunder abnormahloads. ;-'In testimony whereof, .I have hereuntoiset myhand. r V i r V CHAUNGEY MARSH Gnomes;

